This SoC is used in the Raspberry Pi, for example.

Initial support is enough to boot to a serial console, and execute a minimal set of U-Boot commands. No drivers are implemented. For more details, see http://www.broadcom.com/products/BCM2835 or http://www.raspberrypi.org/wp-content/uploads/2012/02/BCM2835-ARM-Peripheral....

Signed-off-by: Stephen Warren swarren@wwwdotorg.org --- arch/arm/cpu/arm1176/bcm2835/Makefile | 37 +++++++++++++++++ arch/arm/cpu/arm1176/bcm2835/config.mk | 19 +++++++++ arch/arm/cpu/arm1176/bcm2835/lowlevel_init.S | 19 +++++++++ arch/arm/cpu/arm1176/bcm2835/reset.c | 27 +++++++++++++ arch/arm/cpu/arm1176/bcm2835/timer.c | 55 ++++++++++++++++++++++++++ arch/arm/include/asm/arch-bcm2835/timer.h | 37 +++++++++++++++++ 6 files changed, 194 insertions(+) create mode 100644 arch/arm/cpu/arm1176/bcm2835/Makefile create mode 100644 arch/arm/cpu/arm1176/bcm2835/config.mk create mode 100644 arch/arm/cpu/arm1176/bcm2835/lowlevel_init.S create mode 100644 arch/arm/cpu/arm1176/bcm2835/reset.c create mode 100644 arch/arm/cpu/arm1176/bcm2835/timer.c create mode 100644 arch/arm/include/asm/arch-bcm2835/timer.h

diff --git a/arch/arm/cpu/arm1176/bcm2835/Makefile b/arch/arm/cpu/arm1176/bcm2835/Makefile new file mode 100644 index 0000000..4ea6d6b --- /dev/null +++ b/arch/arm/cpu/arm1176/bcm2835/Makefile @@ -0,0 +1,37 @@ +# +# See file CREDITS for list of people who contributed to this +# project. +# +# This program is free software; you can redistribute it and/or +# modify it under the terms of the GNU General Public License +# version 2 as published by the Free Software Foundation. +# +# This program is distributed in the hope that it will be useful, but +# WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# + +include $(TOPDIR)/config.mk + +LIB = $(obj)lib$(SOC).o + +SOBJS := lowlevel_init.o +COBJS := reset.o timer.o + +SRCS := $(SOBJS:.o=.c) $(COBJS:.o=.c) +OBJS := $(addprefix $(obj),$(SOBJS) $(COBJS)) + +all: $(obj).depend $(LIB) + +$(LIB): $(OBJS) + $(call cmd_link_o_target, $(OBJS)) + +######################################################################### + +# defines $(obj).depend target +include $(SRCTREE)/rules.mk + +sinclude $(obj).depend + +######################################################################### diff --git a/arch/arm/cpu/arm1176/bcm2835/config.mk b/arch/arm/cpu/arm1176/bcm2835/config.mk new file mode 100644 index 0000000..b87ce24 --- /dev/null +++ b/arch/arm/cpu/arm1176/bcm2835/config.mk @@ -0,0 +1,19 @@ +# +# (C) Copyright 2012 Stephen Warren +# +# See file CREDITS for list of people who contributed to this +# project. +# +# This program is free software; you can redistribute it and/or +# modify it under the terms of the GNU General Public License +# version 2 as published by the Free Software Foundation. +# +# This program is distributed in the hope that it will be useful, but +# WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. + +# Don't attempt to override the target CPU/ABI options; +# the Raspberry Pi toolchain does the right thing by default. +PLATFORM_RELFLAGS := $(filter-out -msoft-float,$(PLATFORM_RELFLAGS)) +PLATFORM_CPPFLAGS := $(filter-out -march=armv5t,$(PLATFORM_CPPFLAGS)) diff --git a/arch/arm/cpu/arm1176/bcm2835/lowlevel_init.S b/arch/arm/cpu/arm1176/bcm2835/lowlevel_init.S new file mode 100644 index 0000000..c7b0843 --- /dev/null +++ b/arch/arm/cpu/arm1176/bcm2835/lowlevel_init.S @@ -0,0 +1,19 @@ +/* + * (C) Copyright 2012 Stephen Warren + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +.globl lowlevel_init +lowlevel_init: + mov pc, lr diff --git a/arch/arm/cpu/arm1176/bcm2835/reset.c b/arch/arm/cpu/arm1176/bcm2835/reset.c new file mode 100644 index 0000000..69c9577 --- /dev/null +++ b/arch/arm/cpu/arm1176/bcm2835/reset.c @@ -0,0 +1,27 @@ +/* + * (C) Copyright 2012 Stephen Warren + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <common.h> +#include <asm/io.h> + +void reset_cpu(ulong addr) +{ + /* + * We should probably use the WDT module here, but an unaligned + * access will do the trick for now. + */ + readl(1); +} diff --git a/arch/arm/cpu/arm1176/bcm2835/timer.c b/arch/arm/cpu/arm1176/bcm2835/timer.c new file mode 100644 index 0000000..d232d7e --- /dev/null +++ b/arch/arm/cpu/arm1176/bcm2835/timer.c @@ -0,0 +1,55 @@ +/* + * (C) Copyright 2012 Stephen Warren + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <common.h> +#include <asm/io.h> +#include <asm/arch/timer.h> + +int timer_init(void) +{ + return 0; +} + +ulong get_timer(ulong base) +{ + struct bcm2835_timer_regs *regs = + (struct bcm2835_timer_regs *)BCM2835_TIMER_PHYSADDR; + + return readl(&regs->clo) - base; +} + +unsigned long long get_ticks(void) +{ + return get_timer(0); +} + +ulong get_tbclk(void) +{ + return CONFIG_SYS_HZ; +} + +void __udelay(unsigned long usec) +{ + ulong endtime; + signed long diff; + + endtime = get_timer(0) + usec; + + do { + ulong now = get_timer(0); + diff = endtime - now; + } while (diff >= 0); +} diff --git a/arch/arm/include/asm/arch-bcm2835/timer.h b/arch/arm/include/asm/arch-bcm2835/timer.h new file mode 100644 index 0000000..30c70e0 --- /dev/null +++ b/arch/arm/include/asm/arch-bcm2835/timer.h @@ -0,0 +1,37 @@ +/* + * (C) Copyright 2012 Stephen Warren + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#ifndef _BCM2835_TIMER_H +#define _BCM2835_TIMER_H + +#define BCM2835_TIMER_PHYSADDR 0x20003000 + +struct bcm2835_timer_regs { + u32 cs; + u32 clo; + u32 chi; + u32 c0; + u32 c1; + u32 c2; + u32 c3; +}; + +#define BCM2835_TIMER_CS_M3 (1 << 3) +#define BCM2835_TIMER_CS_M2 (1 << 2) +#define BCM2835_TIMER_CS_M1 (1 << 1) +#define BCM2835_TIMER_CS_M0 (1 << 0) + +#endif

Note that this affects all users of the ARM1176 CPU that enable CONFIG_ARCH_CPU_INIT, not just the BCM2835 SoC, potentially such as tnetv107x.

Cc: Cyril Chemparathy cyril@ti.com Signed-off-by: Stephen Warren swarren@wwwdotorg.org --- arch/arm/cpu/arm1176/cpu.c | 7 +++++++ 1 file changed, 7 insertions(+)

diff --git a/arch/arm/cpu/arm1176/cpu.c b/arch/arm/cpu/arm1176/cpu.c index c0fd114..532a90b 100644 --- a/arch/arm/cpu/arm1176/cpu.c +++ b/arch/arm/cpu/arm1176/cpu.c @@ -65,3 +65,10 @@ static void cache_flush (void) /* mem barrier to sync things */ asm ("mcr p15, 0, %0, c7, c10, 4": :"r" (0)); } + +int arch_cpu_init(void) +{ + icache_enable(); + + return 0; +}

Use MACH_TYPE_BCM2708 as the Linux machine type for the Raspberry Pi.

The Raspberry Pi actually uses a BCM2835. However, the 2835 this is apparently a SKU in a series for which the BCM2708 is the first or perhaps primary version, such that the 2708 name has historically been used for this purpose.

Extracted from work by Oleksandr Tymoshenko gonzo@bluezbox.com.

Signed-off-by: Stephen Warren swarren@wwwdotorg.org --- include/configs/rpi_b.h | 5 +++++ 1 file changed, 5 insertions(+)

diff --git a/include/configs/rpi_b.h b/include/configs/rpi_b.h index 9020d80..0a3681d 100644 --- a/include/configs/rpi_b.h +++ b/include/configs/rpi_b.h @@ -23,6 +23,11 @@ #define CONFIG_ARM1176 #define CONFIG_BCM2835 #define CONFIG_ARCH_CPU_INIT +/* + * 2835 is a SKU in a series for which the 2708 is the first or primary SoC, + * so 2708 has historically been used rather than a dedicated 2835 ID. + */ +#define CONFIG_MACH_TYPE MACH_TYPE_BCM2708

/* Timer */ #define CONFIG_SYS_HZ 1000000

CONFIG_OF_LIBFDT allows bootm/bootz to pass a device tree to the kernel.

Set bi_boot_params to define where ATAGs will be written (extracted from work by Oleksandr Tymoshenko gonzo@bluezbox.com).

Add ATAG support for bootm/bootz. Newer kernels use device tree, so this isn't that useful. However, old kernels all use board files, so this might still see some use.

Enable bootz command to allow booting a zImage directly.

Signed-off-by: Stephen Warren swarren@wwwdotorg.org --- v2: Squashed the following commits into one: ARM: rpi_b: add ATAG support for bootm/bootz ARM: rpi_b: set bi_boot_params ARM: rpi_b: enable CONFIG_OF_LIBFDT ARM: rpi_b: enabled bootz command --- board/raspberrypi/rpi_b/rpi_b.c | 2 ++ include/configs/rpi_b.h | 8 ++++++++ 2 files changed, 10 insertions(+)

diff --git a/board/raspberrypi/rpi_b/rpi_b.c b/board/raspberrypi/rpi_b/rpi_b.c index f39440f..26df74b 100644 --- a/board/raspberrypi/rpi_b/rpi_b.c +++ b/board/raspberrypi/rpi_b/rpi_b.c @@ -28,5 +28,7 @@ int dram_init(void)

int board_init(void) { + gd->bd->bi_boot_params = 0x100; + return 0; } diff --git a/include/configs/rpi_b.h b/include/configs/rpi_b.h index f34cc03..9c96d0e 100644 --- a/include/configs/rpi_b.h +++ b/include/configs/rpi_b.h @@ -81,10 +81,18 @@

/* Commands */ #include <config_cmd_default.h> +#define CONFIG_CMD_BOOTZ /* Some things don't make sense on this HW or yet */ #undef CONFIG_CMD_FPGA #undef CONFIG_CMD_NET #undef CONFIG_CMD_NFS #undef CONFIG_CMD_SAVEENV

+/* Device tree support for bootm/bootz */ +#define CONFIG_OF_LIBFDT +/* ATAGs support for bootm/bootz */ +#define CONFIG_SETUP_MEMORY_TAGS +#define CONFIG_CMDLINE_TAG +#define CONFIG_INITRD_TAG + #endif

Move the top-of-stack from 32k to near the top of RAM. This leaves the bottom of RAM free for ATAGs, or U-Boot scripts to use as they see fit.

Extracted from work by Oleksandr Tymoshenko gonzo@bluezbox.com.

Signed-off-by: Stephen Warren swarren@wwwdotorg.org --- include/configs/rpi_b.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/include/configs/rpi_b.h b/include/configs/rpi_b.h index 73482d9..33169d3 100644 --- a/include/configs/rpi_b.h +++ b/include/configs/rpi_b.h @@ -44,9 +44,8 @@ * the VC uses. */ #define CONFIG_SYS_SDRAM_SIZE SZ_128M -#define CONFIG_SYS_INIT_RAM_SIZE SZ_4K #define CONFIG_SYS_INIT_SP_ADDR (CONFIG_SYS_SDRAM_BASE + \ - CONFIG_SYS_INIT_RAM_SIZE - \ + CONFIG_SYS_SDRAM_SIZE - \ GENERATED_GBL_DATA_SIZE) #define CONFIG_SYS_MALLOC_LEN SZ_4M #define CONFIG_SYS_MEMTEST_START 0x00100000

From: Vikram Narayanan vikram186@gmail.com

Driver for BCM2835 SoC. This gives the basic functionality of setting/clearing the output.

swarren: * Fix BCM2835_GPIO_BASE; 0x7e200000 is the address on the "VC" CPU, not the ARM CPU. * Fix BCM2835_GPIO_ALT* values to match datasheet. * Invert gpio_request return value. * Add missing & to writel() address parameters in gpio_direction_input(), gpio_direction_output(), and gpio_set_value(). * Fix gpio_direction_input() and gpio_direction_output() to return something, to avoid compiler warnings. * Fix gpio_direction_output() to always call gpio_set_value(), not just when the requested value is 1. * s/bcm_gpio_regs/bcm2835_gpio_regs/g since this driver is specific to BCM2835, and most likely not all Broadcom chips. * Remove FSF address from (c) notices, so we don't have to maintain it. * Fix some indentation errors.

Signed-off-by: Vikram Narayanan vikram186@gmail.com Signed-off-by: Stephen Warren swarren@wwwdotorg.org --- v2: New patch --- arch/arm/include/asm/arch-bcm2835/gpio.h | 66 ++++++++++++++++++++++ drivers/gpio/Makefile | 1 + drivers/gpio/bcm2835_gpio.c | 90 ++++++++++++++++++++++++++++++ 3 files changed, 157 insertions(+) create mode 100644 arch/arm/include/asm/arch-bcm2835/gpio.h create mode 100644 drivers/gpio/bcm2835_gpio.c

diff --git a/arch/arm/include/asm/arch-bcm2835/gpio.h b/arch/arm/include/asm/arch-bcm2835/gpio.h new file mode 100644 index 0000000..c0178cb --- /dev/null +++ b/arch/arm/include/asm/arch-bcm2835/gpio.h @@ -0,0 +1,66 @@ +/* + * Copyright (C) 2012 Vikram Narayananan + * vikram186@gmail.com + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#ifndef _BCM2835_GPIO_H_ +#define _BCM2835_GPIO_H_ + +#define BCM2835_GPIO_BASE 0x20200000 +#define BCM2835_GPIO_COUNT 53 + +#define BCM2835_GPIO_FSEL_MASK 0x7 +#define BCM2835_GPIO_INPUT 0x0 +#define BCM2835_GPIO_OUTPUT 0x1 +#define BCM2835_GPIO_ALT0 0x4 +#define BCM2835_GPIO_ALT1 0x5 +#define BCM2835_GPIO_ALT2 0x6 +#define BCM2835_GPIO_ALT3 0x7 +#define BCM2835_GPIO_ALT4 0x3 +#define BCM2835_GPIO_ALT5 0x2 + +#define BCM2835_GPIO_COMMON_BANK(gpio) ((gpio < 32) ? 0 : 1) +#define BCM2835_GPIO_COMMON_SHIFT(gpio) (gpio & 0x1f) + +#define BCM2835_GPIO_FSEL_BANK(gpio) (gpio / 10) +#define BCM2835_GPIO_FSEL_SHIFT(gpio) ((gpio % 10) * 3) + +struct bcm2835_gpio_regs { + u32 gpfsel[6]; + u32 reserved1; + u32 gpset[2]; + u32 reserved2; + u32 gpclr[2]; + u32 reserved3; + u32 gplev[2]; + u32 reserved4; + u32 gpeds[2]; + u32 reserved5; + u32 gpren[2]; + u32 reserved6; + u32 gpfen[2]; + u32 reserved7; + u32 gphen[2]; + u32 reserved8; + u32 gplen[2]; + u32 reserved9; + u32 gparen[2]; + u32 reserved10; + u32 gppud; + u32 gppudclk[2]; +}; + +#endif /* _BCM2835_GPIO_H_ */ diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index 32a2474..8d2f2b2 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -40,6 +40,7 @@ COBJS-$(CONFIG_TEGRA_GPIO) += tegra_gpio.o COBJS-$(CONFIG_DA8XX_GPIO) += da8xx_gpio.o COBJS-$(CONFIG_ALTERA_PIO) += altera_pio.o COBJS-$(CONFIG_MPC83XX_GPIO) += mpc83xx_gpio.o +COBJS-$(CONFIG_BCM2835_GPIO) += bcm2835_gpio.o

COBJS := $(COBJS-y) SRCS := $(COBJS:.o=.c) diff --git a/drivers/gpio/bcm2835_gpio.c b/drivers/gpio/bcm2835_gpio.c new file mode 100644 index 0000000..6ab2df3 --- /dev/null +++ b/drivers/gpio/bcm2835_gpio.c @@ -0,0 +1,90 @@ +/* + * Copyright (C) 2012 Vikram Narayananan + * vikram186@gmail.com + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <common.h> +#include <asm/gpio.h> +#include <asm/io.h> + +inline int gpio_is_valid(unsigned gpio) +{ + return (gpio < BCM2835_GPIO_COUNT); +} + +int gpio_request(unsigned gpio, const char *label) +{ + return !gpio_is_valid(gpio); +} + +int gpio_free(unsigned gpio) +{ + return 0; +} + +int gpio_direction_input(unsigned gpio) +{ + struct bcm2835_gpio_regs *reg = + (struct bcm2835_gpio_regs *)BCM2835_GPIO_BASE; + unsigned val; + + val = readl(&reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]); + val &= ~(BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio)); + val |= (BCM2835_GPIO_INPUT << BCM2835_GPIO_FSEL_SHIFT(gpio)); + writel(val, &reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]); + + return 0; +} + +int gpio_direction_output(unsigned gpio, int value) +{ + struct bcm2835_gpio_regs *reg = + (struct bcm2835_gpio_regs *)BCM2835_GPIO_BASE; + unsigned val; + + gpio_set_value(gpio, value); + + val = readl(&reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]); + val &= ~(BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio)); + val |= (BCM2835_GPIO_OUTPUT << BCM2835_GPIO_FSEL_SHIFT(gpio)); + writel(val, &reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]); + + return 0; +} + +int gpio_get_value(unsigned gpio) +{ + struct bcm2835_gpio_regs *reg = + (struct bcm2835_gpio_regs *)BCM2835_GPIO_BASE; + unsigned val; + + val = readl(&reg->gplev[BCM2835_GPIO_COMMON_BANK(gpio)]); + + return (val >> BCM2835_GPIO_COMMON_SHIFT(gpio)) & 0x1; +} + +int gpio_set_value(unsigned gpio, int value) +{ + struct bcm2835_gpio_regs *reg = + (struct bcm2835_gpio_regs *)BCM2835_GPIO_BASE; + u32 *output_reg = value ? reg->gpset : reg->gpclr; + + writel(1 << BCM2835_GPIO_COMMON_SHIFT(gpio), + &output_reg[BCM2835_GPIO_COMMON_BANK(gpio)]); + + return 0; +} +